Driving joint for speedometers



Jan. 9, 1923. v 1,441,473

H. A. AMES. DRIVING JOINT FOR SPEEDOMETERS. FILED 001m, 12 j' [922.

Patented.llau.9,1923. i a I c Y UNITED Tarts sa'rn'r OFFICE. "HENRY'AQ Ams, or mrtron, imssaonnsnrr'rs, sssrenon TO s'rnnnaan mannaror mrnnOOIVIPANY, or ronrrann, Marlin, A oonronn'rion or MAI-NE. i imrvrne-JOINT non srEnnowrnrnnsQ.

a lication filed October '12, 1922'. Serial No. 594,130.

Toall whom it may c nc rn; mediate gears and counter shafts have been50,

, Be itknown that vI, HENRY AJAMES, a employed for producing the desireddireccitiZen of the United States, residing at tional relation betweenthe two shafts. The Milton, in the county of Norfolk and State use ofsuch a gear train has necessitated a of Massachusettajhave inventedcertain new driving joint of more or less elaborate conand usefulImprovements in Driving Joints struction, expensive to. manufacture and55 for Speedometers; and I do hereby declare which has proven inpractice incapable of the following to be affull, clear, andexactsuccessfully withstanding the severe jolts description {of theinvention,such as will and strains incidentto road driving. enableothers skilled in the art to which it In the construction of aspeedometer drivappertains to make and use the same. v ing joint whichwill be capable of universal 60 This invention relates to a drivingjoint use with the difierent types of speedometers for fspeedomete'rs. ion the market and also such as to enable it The object of the inventionis to provide a at the same time to withstand severe road 'driving jointfor speedometers of novel and service, certain conditions areencountered durable construction which may be manuwhich complicate themaintenance of the 65 ,facturedeconomically and which is adapted desireddirectional relation between thepin' foruse in connection with thedifi'erent types ion and the main driving shaft or" the speed ofspeedometers at present uponthe market. ometer. For example, the drivingoint in- I With this general object in view, the in cludes, ofnecessity, one shaft secured to the vention consists in the drivingjoint for aXleor other fixedpart of the frame ofthe 7o speedometershereinafter described and'parvehicle in a position such that the pinionticularly defined in the claims. thereon will mesh with the ring gearupon In the drawinvs illustrating the preferred the front wheel ot thevehicle. The mechaembodiment of file invention, Figure ,1 is a nism fortransmitting the rotations of this plan view, partly in section, of theimproved pinion to the flexible shaft of the speed- 75 joint; vand Fig.2 is a sectional view of the ometer, must be such as to afford anangular same on the line 2+20r Fig. 1. connection with suchtlexibleshaft. Swivel The'sp'eedometers used'in connection with joints have beenattempted but the wear [motor vehicles arefdriven from a rotating underroad service is such as'to render a part of the vehicle,'usually one ofthe front more rigid construction desirable. In prac- 0 wheels',bym'eansiof a ring gear upon'the tice, for successful operation, theangular front wheel and pinion cooperating thereconnection shouldbe inthe neighborhood with, and thence 'throughconnections inof 120 degrees,reasonable variations therecludinga driving joint and flexible shaft tofrom not affecting the successful operation the speedindicatinganddistancerecording 'ofthe joint to an appreciable extent. In 35 mechanismof the "speedometer, the latter accordance with the'present invention,the positioned upon the cowl or] dash of the vedesired rigidity anddurability, as well as hicle. Some'types of speedometer-s require thedesired directional relation, is secured 40 that their main drivingshaft be rotated in by a drivingjointvcomprising two shafts,

a single direction for-their operation. Other one provided with a piniontor'engagemen't types may be successfully driven whether with the ringgear upon the'vehicle wheel, their driving shaft is rotated clockwise orand the other with suitable" connection to anti-clockwise "In thedriving joints herethe flexible driving shaft of the speedometer.

4 5 tofore em 10 ed for transmittin the rota- The shatts'are arran edat-an angle of a 'tions ofthe pinion, in'a'manner'such'that proximately120 degrees with relation to one the driving of the speedometer shaftand another, each being journaled in bearings pinion are both causeditorotate in the same rigid in a single unitary housing. The direction,various combinations of intershafts are connected by a'singlepair ofcooperating oblique worm gears within the housing, one upon each shaftThe worm gears are specially designed in accordance with the angularrelation of the two shafts to produce rotation of both in the samedirection. Tn thismanner a simple yet practical construction of drivingjoint is secured.

In the illustrated embodiment of the invention, the twoshafts are shownat 10 and 12, extending intoand journaled in bearings in a unitaryhousing 14, preferably comprising a single casting.-- The-tubular member15 supports and forms the bearing for the shaft 10, being received in anopening in the housing 14 and secured therein by adrive fit. The housing14; is adapted tobe secured by the clip bracket 16, which clamps thetubular member to the axle or frame of the vehicle in the usual manner.One shaft 10 is provided with a pinion 18 secured thereon which isadapted to engage and mesh with the usualring gear (not shown) upon thefront wheel of the vehicle. The second shaft 12 has a slot 13 forconnection to the usual flexible driving shaft of the speedometer. Theunitary housing 14 is provided with hollow cylindrical portions 2022angularly inclined to one another and each of which is provided with anopen end 23 adapted to be closed by the end bearing 25 in which the endsof the shafts are journaled. These end bearings are secured in place bya drive fit in the open ends of the housing to form a rigidconstruction. One of the end bearings is provided with a grease cup 24.Upon each of the shafts 10 and 12 and within the housing 14, the worm 26and the spiral gear 28 are secured. These gears are designed withrespect to the angular inclination of the two shafts 10 and 12 to securea rotation of the pinion and its shaft in one direction to produce arotation of the shaft 12 inthe same direction. In this manner thedesired directional relation between the rotation of the two shafts issecured by the use of a single pair of gears, thus en'- abling theconstruction of the entire driving joint to be simple and extremelyrigid. The construction of the housing is such as to enable the joint tobe assembled in a convenient and simple manner, the worm gears beingslipped through the open ends 23 into the interior of the housing. Theworm gear 26 is a right hand four thread worm, and the worm gear 28 is aright hand ten thread worm. Obviously, therefore, the worm26 iscomparatively a slow traverse worm with respect to the worm or spiralgear 28, and

.the result of this is that the connection is irreversible from thespeedometer end. Thus while the gear 26 may be rotated in eitherdirection to drive the driven gear '28, the latter has such tooth anglewith relation to the driving worm 26 that is cannot turn the latter.This driving joint is rigid, durable and of construction facilitatingeasy assembly. Thus the tubular member 15 is forced into the mouth ofthe housing let and secured in place by such driving fit. The shaft 10of the drivingworm 26 is dropped into the bearing in the tubular member,and then the closure 25 or end bearing is forced into place in theopposite opening of the housing. This closure is provided Wit-h anopening, and a grease cup affords means for introducing lubricant to theworms. Then the -shaftand the other gear are simply dropped into placeand the closure is forced in the other opening, and thus the device ispermanently assembled and. the parts are always maintained in goodworking relation.

Having thus described the invention, what is claimed is: o

1. A driving joint for speedometerscomprising a'housing having two holestherethrough arranged at an angle of approximately 120 with respect toeach other and at a distance from each other, two shafts supported inthe holes in the housing, the 90 first being provided with a relativelyslow traverse worm or spiral gear, the other being provided with arelatively quick traverse worm or spiral gear, both gears having thesame kindof thread or teeth,. the first shaft being adapted to be drivenby the vehicle, and the second shaft being adapted ,for connection withthe driving shaft of the speedometer, the angular arrangement of theworm threads or spiral gear teeth being such that both shafts rotate inthe same direction bythe application of power to the first shaft,whereby speed reduction is secured between the first shaft and thesecond shaft. i I v 2. A driving joint for speedometers'comprising ahousing having two holes therethrough, a tubular member supported inioneend of one hole and constituting a bearing, a shaft mounted in saidbearing provided .110 with a slow traverse worm or gear, a second shaftmounted in the ot'her hole in the housing provided with aquick'traverse.gear,'the ends of the holes being closed'by end bearingstaking against the ends of the shafts, .115 and forming end bearings forthe shafts, the threadsof both, gears being right hand so that powerapplied to the first shaft rotates the second shaft in the samedirection and because of their respective forms of 120 traverse, at areduced speed ratio.

vided with a second hole offset vfrom the first hole and arranged atanangle of about 120 with relation thereto, said hole being enlargedopposite the gear on the first shaft, 5 a driven shaft mounted in thereduced portion of the second hole, a quick traverse spiral gear mountedon said shaft and located in the enlarged portion of the hole, an

end bearing closing such enlarged portion,

the housing at the end ofthe reduced por- 10 tion I of such hole beingprovided with means for attachmentto the casing of the speedometerdriving shaft. I

HENRY A. AMES;

